iOS SHA加密算法的实现

- (NSString *)SHAStringWithSourceData:(NSData *)data type:(SHAType)type{

    int shaDigestLength;
    switch (type) {
        case SHAType_sha1: shaDigestLength = CC_SHA1_DIGEST_LENGTH; break;
        case SHAType_sha224: shaDigestLength = CC_SHA224_DIGEST_LENGTH; break;
        case SHAType_sha256: shaDigestLength = CC_SHA256_DIGEST_LENGTH; break;
        case SHAType_sha384: shaDigestLength = CC_SHA384_DIGEST_LENGTH; break;
        case SHAType_sha512: shaDigestLength = CC_SHA512_DIGEST_LENGTH; break;
        default: break;
    }

    uint8_t digest[shaDigestLength];
    switch (type) {
        case SHAType_sha1: CC_SHA1(data.bytes, (CC_LONG)data.length, digest); break;
        case SHAType_sha224: CC_SHA224(data.bytes, (CC_LONG)data.length, digest); break;
        case SHAType_sha256: CC_SHA256(data.bytes, (CC_LONG)data.length, digest); break;
        case SHAType_sha384: CC_SHA384(data.bytes, (CC_LONG)data.length, digest); break;
        case SHAType_sha512: CC_SHA512(data.bytes, (CC_LONG)data.length, digest); break;
        default: break;
    }

    NSMutableString* output = [NSMutableString stringWithCapacity:shaDigestLength * 2];
    for(int i = 0; i < shaDigestLength; i++)
        [output appendFormat:@"%02x", digest[i]];

    return output;
}